Single-Source Contingency

See the ISO New England Inc. Transmission, Markets, and Services Tariff, Attachment G Procedure to Protect for the Loss of Phase II Imports, which describes the process used by ISO New England, New York ISO, and PJM to monitor their respective systems and provide the data required by ISO New England to calculate import limits on the Phase I/II high-voltage direct-current interconnection between it and Hydro-Québec TransÉnergie.

Download a report on single-source contingencies, limits placed on external and generation interfaces in which losing a single piece of equipment could cause a loss of 1,200 or greater megawatts (MW).

The single-source contingency limit is the base limit plus the authorized margin multiplied by the margin sensitivity. The NY Central-East single-source contingency limit is based on the authorized margin divided by the Distribution Factor (0.30). The margin associated with NY Station Voltages has been converted to MW.

Note: The compilation of this data has various origins and is provided for the convenience of the New England market participants. The ISO does not assume responsibility for the accuracy.

 
Single-Source Contingency
Description Timestamp Download
Current - August 27, 2025 08/27/2025 07:36 PM EDT CSV
August 13, 2025 08/13/2025 11:56 PM EDT CSV
August 14, 2025 08/14/2025 11:56 PM EDT CSV
August 15, 2025 08/15/2025 11:56 PM EDT CSV
August 16, 2025 08/16/2025 11:56 PM EDT CSV
August 17, 2025 08/17/2025 11:56 PM EDT CSV
August 18, 2025 08/18/2025 11:56 PM EDT CSV
August 19, 2025 08/19/2025 11:56 PM EDT CSV
August 20, 2025 08/20/2025 11:56 PM EDT CSV
August 21, 2025 08/21/2025 11:56 PM EDT CSV
August 22, 2025 08/22/2025 11:56 PM EDT CSV
August 23, 2025 08/23/2025 11:56 PM EDT CSV
August 24, 2025 08/24/2025 11:56 PM EDT CSV
August 25, 2025 08/25/2025 11:56 PM EDT CSV
August 26, 2025 08/26/2025 11:56 PM EDT CSV